This browser-based emulator is the easiest way I've found to play retro games

Afterplay is a browser-based retro game emulator that supports a wide range of consoles from the Atari 2600 and Commodore 64 up to the Nintendo 64, Nintendo DS, and Sega Saturn. It offers cloud save syncing, automatic box art fetching, cheats, multiplayer, and controller support without requiring any software installation. Users can batch-import existing ROM libraries, and the platform also sells new games developed for classic consoles through partnerships with retro publishers. While not the most feature-rich emulator, its ease of use and convenience make it a compelling option for casual retro gaming sessions.